West Bengal finance minister Amit Mitra was heckled and had his shirt torn off by Students Federation of India activists outside the Planning Commission in New Delhi on Tuesday.

The SFI activists were protesting the death of Sudipto Gupta, a member of their organisation in police custody in Kolkata earlier this month.

The agitated students carrying placards also pushed Mitra around and shouted slogans as he tried to enter the office in the heart of the city to meet Planning Commission deputy chairman Montek Singh Ahluwalia.

In the melee, his white kurta was torn.

A fuming West Bengal chief minister Mamata Banerjee, who was to meet Ahluwalia to finalise the annual plan 2013-14 for the state, described the protest as "dirty politics".

Banerjee, who was advised by police not to get down from her car and drive inside, however, chose to walk through the slogan-shouting and placard-wielding crowd into the building.

"This is dirty politics. These are hooligans," she said.

Panchayat minister Subrata Mukherjee and urban development minister Firhad Hakim also faced the ire of the activists who were protesting the death of Sudipto Gupta, a leader of CPI(M)'s student wing SFI.

"You know why they are protesting. I have 10 lakh people with me. I can bring them to Delhi. They don't want development of West Bengal," she said.

Irked by the scene that unfolded outside, she complained to Ahluwalia, "You have created a new precedent. My minister was assaulted. This is scandalous. There were 20 hooligans. Can you stop development of a state like this."

SFI leader Ritabrata Banerjee said, "Our protest is to show Mamata Banerjee that Sudipto Gupta's death was not a petty matter. People are deeply concerned about what is happening in West Bengal."

SFI has alleged that 22-year-old Gupta died after he was beaten up by the police which has maintained that he was killed in an accident.

Banerjee had termed the incident as "unfortunate" but later called it a "petty" matter, drawing criticism from the Left.

Said a protestor Sunand: "We demonstrated near the Yojna Bhavan. But if someone's shirt is torn in the melee, we are sorry for that."

The protest followed the death in police custody of Students Federation of India leader Sudipta Gupta in Kolkata April 2.

Police in Kolkata insist that the young man was killed when his head struck an electric post while being taken in a bus.

The SFI has alleged that he was beaten by policemen, forcing him to fall off the bus and suffer serious injuries that led to his death.